Both reported short sleep and reported long sleep are major predictors of excess mortality risk, but the import of reported sleep duration as a risk factor is not yet known. Sleep-related risks are of special interest to The Women's Health Initiative (WHI), because insomnia increases among women at menopause, and because WHI's hormone replacement therapy (HRT) and dietary modification (DM) may influence sleep. The WHI will be an exciting opportunity to examine whether risks associated with reported sleep durations can be explained by a selection of intercurrent conditions, but the broad WHI design will not control for important potential confounders. Explicitly, the broad WHI design by itself cannot determine if behaviorally-modifiable objective sleep durations are the primary risk factor. This ancillary project will supplement th WHI Observational Study (OS) by performing additional examinations on 600 San Diego OS women. These volunteers will undergo home sleep recordings, hormone measurement, and detailed psychiatric interviews. To facilitate distinction of affective and sleep factors in WHI outcomes, the types and severity of depression in the OS subsample and the validity and reliability of sleep items i questionnaires given to WHI women will be examined. The ancillary studies will determine whether objectively recorded sleep durations are mortality risk factors, whether sleep duration can be distinguished from depression as a risk factor in WHI data, and whether sleep-associated risks are attributable to specific pathophysiologic processes such as sleep apnea, circadian rhythm phase advances, deficiencies of melatonin, or deficiencies of melatonin, or deficiencies of reproductive steroids.